Single-Cell Transcriptome Analysis Maps the Developmental Track of the Human Heart

The heart is the central organ of the circulatory system, and its proper development is vital for maintaining human life. Here we used single-cell RNA-sequencing to profile the gene expression landscapes of ~4,000 cardiac cells from human embryos and identified four major types of cells: cardiomyocytes (CMs), cardiac fibroblasts, endothelial cells (EC) and valvar interstitial cells (VICs). During heart development, atrial and ventricular CMs acquired distinct features early in development. Furthermore, both CMs and fibroblasts show stepwise changes in gene expression. As development proceeds, VICs might be involved in the remodeling phase, and ECs display location-specific characteristics. Finally, we compared gene expression profiles between human and mouse and identified a serial of unique features of human heart development. Our study lays the groundwork for elucidating the mechanisms of in vivo human cardiac development and provides potential clues to understand cardiac regeneration. The gene expression pattern of our data can be easily viewed and navigated at https://tanglab.shinyapps.io/human_fetal_heart_scRNA/. Overall design: single cell RNA seq data set 1: 77 samples single cell RNA seq data set 2: 21 samples